3 1 2 2 1 1
1 3 1 1 2 2 2 1
Speak each digit aloud in your head to understand the logic.
In line no. 1, there is only 1 written. So speaking this out as "one ones" we shall get line no. 2 as 1 1.
Now here there is "two ones" that is 2 1 which is the next line.
Then we have "one twos, one ones" that is 1 2 1 1 which is the next line.
Now, we have "one ones, one twos, two ones" that is 1 1 1 2 2 1, which is the next line.
Similarly, continuing in this manner, we get the nest line as "three ones, two twos, one ones" that is 3 1 2 2 1 1.
Hence the next line will be 1 3 1 1 2 2 2 1
